Method of operating oil-wells.



C. VA. WAITZ.

METHOD OF OPERATING OIL WELLS. APPLIcATioN FILED MAR.2`2.1911.

1295343. *arented Fel; 25, 1919.

2 SHEETS-SHEET 2.

CHARLES A. WAITZ, OF ROUSEVILLE, 'PENNSYLVANIA.

METHOD OF OPERATING OIL-WELL S.

Specification of Letters Patent.

` Patemeu Feb. 25, 1919.

application fiiea March 22,, 1917. serial No. 156,572.

To all whom z't may concern:

Be 'it known that I, CHARLES A. WArrz, a citizen of the United States, residing at Rouseville,.-infthe county of Venango and State .of Pennsylvania, have invented new and useful Improvements in Methods of Operating Oil-Wells, of Which the following is a specification. v

This invention relates to methods of operating oil Wells and consists in certain improvements therein as will be hereinafter fully described and pointecl out in the claims.

The object of the invention is to facilitate the removal of the oil from oil-hearing sands.

In the accompanying drawings I have shown a group of oil Wells and mechanism for carrying out the method as followsz- Figure 1 shows a plan vieW of an oil field. p Fig. 2l a vertical section of two Wells in the field illustrative of the apparatus used in carrying out the method.

1 marks an` oil field, the boundary line being at 2.' A group of Wells 3`are arranged within the boundary line 2 and a number of competing Wells 4 are arranged Without the boundary. Two Wells 5 and 6 arranged Within'the group are selected for introducing pressure to the Sands. These two Wells preferably are about the same distance apart as they are from the boundary lines. These Wells tap a plurality of sands as shown 7, 8 and 9. The Wells are provided With the usual casing 10, casingheads 11 and tubing 172. It Will be understood that each Well of the group has or may have a casing, casing head and tubing.

- In carrying out my method I place the Well 6 under pressure, preferably a very high pressure, say up to five or six hundred pounds. This drives the oil away from'the Well 6 and toward the boundaries of the field. As -the different Wells in the 'group feel the effect of this vpressure the oil is removed. When it becomes apparent that the pressure is Adriving the oil to a point adjacentto the Wells near the boundary I re- Verse the operation on the Well 6 and place this Well under a partial vacuum, thus lreversing the flow of oil .through the sand and' taking it up from Well to well in the group. It is preferable as the pressure is exhausted i Ifrom the Well 6 to introduce it to another Well, thus utilizing the gas instead'of the air as a 'rule and also :saving some of the energy necessary to effect the result. I', therefore, introduce the pressure as the gas is exhaustedfrom the Well 6 into another well 5 and in placing the Wells 5 and 6 it is desirable as before 'stated, to have them as distant rom each other as they are from the boundary and'preferably a little greater distance Vapart so that they Will cover the i intervening territory in a natural manner.

In order to carry out this pressure scheme I provide 'the compressor 13 With the dis-` charge 14z and intake 15. I connect the pipes 12 with the discharge 14 by a pipe 16. I supplythe bypass 18- Which is connected With the intake 15 by a pipe 19. I provide the valves 17-17 at each side of the pipe 16 and the valves 20-20 in the bypass at each side of the pipe 19. By closing one ofthe valves 17 and one of the valves 20, as for instance the right-hand Valve 17 and the left-hand' Valve 20, the gas draWn in from one Well is discharged to the other Well and by -reversing'lthe position of the valves 17 and 20; 'that is, closing one Valve 17 and sand ofifering the least resistance. This may be the sand `having the least amount of oil and consequentl this result sho ld be avoided. To obvlate this I provide a. acker 21 on the tubing 12. By placingthis packer over the lower sand, pressure may be Iput on the lower sand alone. After the oil is taken from the lower sand this mayfbe cemented or plugged, the packer put above'the net sand, as shown the sand 8' andthe oiltaken from it. In ,carrying' out this, it' is desirable to not only pack ofl' the Well'to which pressure is introduced but also 'theadjacent Wells in the group. After'thepressure has .crowded the oil beyondtlfe, Wells immediately .adjacent the air' mayesoape through the connection afi'orded'byjsaid Wells into osl the sands having least resistance so that the v result Will notibe fully achieved. It is desirable, therefore, not only to pack of the Well to which pressure is`immediately suppliedl but also the wel'ls as they extend out through the group. This same action, packplaced lto ing ofl', is desirable in theV Well` Which is under a partial vacuum but, of course, the necessity for it is not so great With such a Well as With the Well to Which the high pressure is applied.

I prefer to open lthe Sands prior to the introduction of the air by lintroducing an eX- plosive material in the vicinity of a sand Which is being operated upon. yIn doing this I utilize the ordinary torpedo for this purpose.

I also prefer to Iintroduce benzin to the Well to clear. the sand of paraffin.

It Will be understood that pressure is put on the Well 6 and then the pressure eX- liausted as the oil reaches the outer Wells of the group so as to reverse the floW of oil and that this operation is repeated `so` that the oil is forced back and Vforth through the sand until it is exhausted beyond a point' Where it is profitable to remove it.

VI prefer lto use natural gas as the medium for exerting pressure on the Wells and Where this is done the gas introduced to the Well exerts the -pressure and thenWhen the operation is reversed this gas is removed. The

Iarly in vieW of the fact'that it is under pressure, takes up a certain amount of the more volatile parts of the oil so that When removed it carries With it these'parts, such as gasolene, Which gasolene may be separated from the gas and the gas'again used Ifor exerting pressure (in the Well. ,To accomplish this in the accompanying structure, I have provided the' gasolene separator 22. This is simply a U-bend surrounded by a chilling mediumv23,4usually a brinel or other liquid ordinarily used in connection With ice machines. The 'gasolene Which accumulates is draWn ofi through the pipe 24 and stored in Vthe tank25. In order that the gas in the separator 22 may be under' sufficient pressure to readily separate the gasolene, I. provide a valve 16a. This may be a differential valve Which permits the passage of gas only When the pressure back of it reaches a certain volume or an ordinary Valve so nearly closed in vieW of the volume of gas as to maintain the pressure.`

It may be desirable to transfer the gas from one Well to another so as to equalize the pressure, thus saving pumping. This v may be done in the present instanceby clos- Uas so forced into the sand strata, particu- 1 general location and removing the oil from p the Wells having the lesser pressure.

2. The method of operating a group of oil Wells Which consists in exerting pressure upon a Well Within the group until the pressure begins to move the oil past the outer Wells of the group and then subjecting the sand from a point Within the group to a partial vacuum to reverse the floW of oil.

3. The method of operating a group of oil Wells Which consists in torpedoing the Wells to loosen the sand therein, then alternately subjecting the oil sand tapped by said Wells to pressure and a partial vacuum from one general location and removing the oil from the Wells having the lesser pressure.

4. The method of operating a group of oil Wells Whichl consists in forming a partialV vacuum in the first Well, putting a' second Well under pressure, then alternating the pressure in these Wells, first equalizing `the pressure bydirectly connecting the Wells, and removing the oil from the Well having the lesser pressure..

5. The method of operating a group of oil Wells Which consists in alternately subjecting the oil sand tapped by said Wells to gas pressure and a 'partial vacuum, removing the 'oil from the Well having the lesser pressure, and' removing the gasolene from the gas utilized in the operation.

6. The method of operating an oil Well Which consists in alternately subjecting an oil sand tapped by said Well to pressure and a partial vacuum, andremoving the'oil accumulated in said Well While under a partial vacuum.

In testimony Whereof I have 'hereunto set my hand.

` CHARLES A. -WArrz. 

